CME Group, the largest U.S. futures exchange operator, had no immediate comment on the executives salaries.

Duffy, whose prior contract was due to expire at the end of 2015, will remain in his position through the end of 2017, according to the extended employment contract. Gill, whose prior contract ran through the end of this year, will retain his post as CEO through the end of 2016.

Duffy received a pay raise to $1.25 million from $1 million when he took on the title of president in 2012. Gill's salary jumped to $1 million level from $800,000 when he was promoted to CEO from president in 2012.

CME Group, which runs the Chicago Mercantile Exchange and the New York Mercantile Exchange among others, competes with IntercontinentalExchange Group Inc, which recently boosted its international profile with the acquisition of NYSE Euronext.

CME Group last week reported higher earnings for the fourth quarter, although the financial results fell short of analysts' estimates.

The company is planning to launch its first overseas exchange in London this year.